- Among congenital heart disease diagnosed in adulthood, 30%-40% are ASD1,2
- In pediatric patients, 61% of ASDs present as complex lesions3
- Adults with unrepaired secundum defect have reduced exercise capacity of 50%-60%1
- Untreated large secundum ASD annual mortality rates:1
- For patients in their 40s: 4.5%
- For patients in their 60s: 7.5%
One study examined long-term mortality of adult ASD patients with and without closure of the defect. The findings reveal that mortality overall was higher among ASD patients without closure compared to patients who had ASD closure, and cardiac deaths were significantly higher
(p < 0.01). For instance, heart failure accounted for 12% of deaths in non-closure patients v.s 2.5% among patients who had ASD closure.4
- Secundum ASD (75% of cases) in the region of the fossa ovalis
- Primum ASD (15% to 20%) located inferiorly near the crux of the heart
- Sinus venosus ASD (5% to 10%) located near:
- Superior vena cava entry
- Inferior vena cava entry
- Coronary sinus defect (less than 1%) which causes shunting through the coronary sinus ostium
About 65%-70% of patients with a secundum defect are female.1
Most such defects have no identifiable cause, but certain genetic abnormalities have been linked to ASDs. The risk of a secundum defect in particular is increased in families with a history of congenital heart disease—particularly when ASD has also been diagnosed in a sibling.1
ASDs have been associated with maternal characteristics and behaviors such as:1
- Fetal alcohol syndrome
- Cigarette smoking, particularly in the first trimester
- Advanced maternal age (≥ 35)
- Certain antidepressant use
Most children with isolated ASDs are asymptomatic. If patients are untreated, however, symptoms can occur in adulthood.1
The consequence of a left-to-right shunt across an ASD is right ventricular volume overload and pulmonary over-circulation. Patients who have large atrial shunts can experience symptoms related to excess pulmonary blood flow and right-sided heart failure. In infants, children, and young adults up to approximately age 20, symptoms may include:
- Heart murmur (followed up with echocardiogram)
- Frequent respiratory infections
- Slow weight gain
In older adults ASDs may present with symptoms of:
- Fatigue and exercise intolerance
- Atrial arrhythmias—atrial flutter, atrial fibrillation, and sick sinus syndrome
- Peripheral edema
- Cardiomegaly on routine chest x-ray
- More audible murmur during pregnancy
- Paradoxical embolism
Patients who have small defects (< 10 mm) have minimal to no enlargement of the right heart structures, and these patients can remain asymptomatic into their 40s or 50s. But even these patients may develop symptoms with increasing age. Symptoms appear over time for several reasons—in 18% of cases because of an increase in the size of the defect (although this is more likely to occur in those who initially have larger defects).1 Increased shunting can also be a factor, caused by a decrease in left ventricular (LV) compliance as the patient develops coronary artery disease, hypertension, or acquired valvular disease.
Because many patients experience the gradual onset of symptoms—and may exhibit only subtle physical findings—late diagnosis can occur in patients with ASDs. Proper attention to symptom presentation can preclude late diagnosis, which puts patient at higher risk for arrhythmias, pulmonary arterial hypertension, LV systolic dysfunction, and paradoxical embolism.
Transthoracic echocardiography (TTE) is the primary imaging modality for an ASD. Clinicians should visualize the entire atrial septum, from the orifice of the superior vena cava to the orifice of the inferior vena cava. This is important given that poor quality transthoracic images can produce false-negative diagnoses, which can be relatively common.
Percutaneous device or surgical closure are the mainstays of therapy in patients with hemodynamic or clinical consequences of the defect. However, severe pulmonary arterial hypertension (PAH) is a contraindication to closure.6 Percutaneous closure is the treatment of choice in the majority of cases of secundum ASDs.5
Patients who do not undergo ASD closure have worse long-term outcomes, including more atrial arrhythmias, increasingly reduced functional capacity, and eventually greater degrees of PAH.6
The information provided is not intended for medical diagnosis or treatment as a substitute for professional advice. Consult with a physician or qualified healthcare provider for appropriate medical advices.
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- Geva T, et al. Atrial septal defects. Lancet. 2014;383:1921-1932.
- Adler DH. Atrial septal defect. Medscape. https://emedicine.medscape.com/article/162914-workup#showall.
- Shuler CO, et al. Prevalence of treatment, risk factors, and management of atrial septal defects in a pediatric Medicaid cohort. Pediatr Cardiol. 2013;34(7):1723-1728. doi: 10.1007/s00246-013-0705-5.
- Nyboe C, et al. Long-term mortality in patients with atrial septal defect: a nationwide cohort-study. Eur Heart J. 2018;39:993-998. doi:10.1093/eurheartj/ehx687.
- Kashour TS, et al. Successful percutaneous closure of a secundum atrial septal defect through femoral approach in a patient with interrupted inferior vena cava. Congenit Heart Dis. 2010;5:620–623.
- Stout KK, et al. 2018 AHA/ACC Guideline for the Management of Adults with Congenital Heart Disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2018;000:e000-e000. doi: 10.1161/CIR.0000000000000603.